The present invention refers in general to a device to measure and control the conditions of stability of an industrial vehicle and, in particular, a device to measure the forces, in particular the vertical forces, applied to each wheel hub of the two axles to analyse the operating and stability specifications of an industrial lifting vehicle.
A non-limiting preferred example of an embodiment of this invention proposes a device to measure and a system to control the conditions of stability of industrial vehicles, whether static, in movement or during the operating phases to manoeuvre or move the load, if present.
During manoeuvre operations of an industrial vehicle with no suspensions, the entire casing or chassis of the vehicle reacts to the various external stresses, determined by a series of forces and overturning moments, caused either by movement of the load or variation in the stability of the vehicle in motion on the ground.
All this can be performed during static, almost-static or dynamic conditions of use. Measurement of external physical sizes is useful to determine the conditions of operation and stability of the vehicle.
For example, it is possible to measure the vertical forces and overturning moments in the various directions to calculate the stability of industrial vehicles with axles connected to the chassis without interposition of suspensions, during the various manoeuvres of turning, braking, acceleration or lifting the load, in order to calculate the induced forces and the moments of destabilisation of the vehicle. Currently, the operation to measure these forces and moments can be performed using specifically designed measurement instruments, only by simulation to be performed in the laboratory.
Moreover, to date, the various physical sizes of interest are measured approximately and placed in relation to one another by means of force transducers, which are fixed only externally to the casing of the axle or the chassis of the vehicle, thus influenced by all possible effects of disturbance or drift of the signal to be measured, which can be influenced by the effects of temperature, deflections of the system, operating pressures of the brakes, resulting in inaccurate and unreliable final information.
Therefore, fitting these transducers in specific positions of each rotating axle does not permit accurate measurements, as they are influenced by many external factors, in addition to those intrinsic to the geometry of the axle or the coupling of the axle with the vehicle chassis.
Lastly, all this requires the development of complex transformation algorithms, suitable to translate the position through time of each vehicle axle into the fixed coordinates system of the vehicle.
The object of the present invention is, therefore, to solve the problems mentioned above and, in particular, to identify a device for measurement and control of the conditions of stability of a vehicle, in particular an industrial vehicle, which allows an indication of stability to be shown following suitable processing of signals emitted by specific measurement instruments integrated in one or more structural components of the axle.
Another object of the present invention is to produce a device for measurement and control of the conditions of stability of a vehicle, in particular an industrial vehicle, which allows disabling of all manoeuvres that can be controlled by the operator that can cause consequent instabilities of the vehicle.
A further object of the present invention is to produce a device for measurement and control of the conditions of stability of a vehicle, in particular an industrial vehicle, which allows all limit conditions of static instability of the vehicle to be indicated, also in the presence of loads and of straddles for lifting materials, in any operating position of the arm of the vehicle.
Yet another object of the present invention is to produce a device for measurement and control of the conditions of stability of a vehicle, in particular an industrial vehicle, of the automatic type, which is safer and more reliable than traditional indirect measurement and control devices.
These and other objects are achieved by a device for measurement and control of the conditions of stability of a vehicle, in particular an industrial vehicle, as claimed in claim 1, which is referred to for brevity.
Advantageously, the invention refers to the fact that it envisages the integration of one or more transducers and, in particular, one or more directional load cells, on each pin of the articulated joint of the steering xe2x80x9cpivotxe2x80x9d of the axle, said pin being provided at the level of the supports of the vehicle wheel hubs, thus making a measurement instrument of a structural component of the axle of a four wheel vehicle.
Moreover, the present invention can be advantageously adapted in order to read the stability data continuously, in order to perform, in real time, any type of stability test during operation of the vehicle. The device according to the invention comprises a series of load cells, integrated at the level of the hubs of each axle.
Lastly, an electronic operating device processes, by means of suitable control software, the signals transmitted by each cell, appropriately amplified, in order to calculate the stability of the structure in real time and, therefore, if necessary provide a command to disable specific vehicle functions if the aforesaid processing supplies results with a spatial stability value beyond a certain safety area (base stability area).
This condition of danger can be suitably indicated to the vehicle operator, by means of an acoustic and/or visual warning device positioned on the front of the instrument panel.